Multi-action front end loaders



March 1952 w. E. ALBERT EI'AL 3,024,933

MULTI-ACTION FRONT END LOADERS Filed March 3, 1958 7 Sheets-Sheet 1 HVVENTUR$ 60M 2/ WW March 13, 1962 w. E. ALBERT ET AL 3,024,933

MULTI-AC'IION FRONT END LOADERS Filed March 3, 1958 '7 Sheets-Sheet 2 6 011mm 4 .dfe

March 13, 1962 w. E. ALBERT ETAL 3,024,933

MULTI-ACTION FRONT END LOADERS Filed March 3, 1958 '7 Sheets-Sheet 3 ZNVENTORS.

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MULTI-ACTION FRONT END LOADERS Filed March 3, 1958 7 Sheets-Sheet 4 INVENTORS.

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March 13, 1962 w. E. ALBERT ET AL 3,024,933

MULTI-ACTION FRONT END LOADERS Filed March 3, 1958 '7 Sheets-Sheet 6 INVENTORS. 6: WM

March 13, 1962 w. E. ALBERT ETAL 3,024,933

MULTI-ACTION FRONT END LOADERS '7 Sheets-Sheet 7 Filed March 5, 1958 INVENTORS.

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ilnited States Patent Ofice 3,024,933 MULTI-ACTION FRONT END LOADERS Wiliiarn E. Albert, Eensenville, and Wilbum K. Brown,

Chicago, lllh, assignors to Pettibone-Mulliken Corporation, Chicago, fill, a corporation of Delaware Filed Mar. 3, 1958, Ser. No. 718,556 7 Claims. (Cl. 214-701) Front end or lift-fork loaders for use on rugged terrain can be much more eflicient than those now available if they have various manipulating functions. The present invention provides such a loader, and a hydraulic system for controlling its functions. In some of its aspects it is especially suitable for use in conjunction with the reaching type of front end loader which was the subject of an application recently filed by one of the present inventors, William E. Albert, Serial No. 681,306, filed August 30, 1957. As shown in that application, there is carried at the end of the boom a primary frame which can be tilted as for dumping, This frame is commonly called an A frame, probably because some of its predecessors were of A shape.

According to the present invention, a carriage which moves laterally from side to side is carried by the A frame, and a tilt table which is laterally pivoted is carried by the carriage, the tilt table carrying the load engaging means such as a fork or rack. Hydraulic cylinder means are provided for separately powering all of the movements here indicated. A pair of hydraulic cylinders tilts the A frame on the boom, another pair of hydraulic cylinders raises or lowers the boom, and a third pair of hydraulic cylinders pivots a link structure by which the boom is carried for making the boom reach or retract. Also front and rear hydraulic steering is provided. It is very important that the hydraulic fluid for each function be separately controlled, and it is desirable that each boom cylinder be independently supplied with hydraulic fluid under pressure, with equal supply to each cylinder, so that they will be raised uniformly even if the load is unbalanced. Separate pumps for each of the many functions would tend to be prohibitive. According to the present invention all of these various hydraulic requirements are satisfactorily met with the aid of only two double pumps. In no instance is it necessary to connect the same pump to two hydraulic devices which should operate at the same time and may have very different loads, and thus there is avoided the danger that during such simultaneous operation too much of the flow from the common pump would go to the hydraulic means subjected to the lowest pressure.

Additional objects of the invention will be apparent from the following description of the drawings.

Designation of Figures The figures are not in all respects consistent with one another. Some parts are omitted where not needed for the purpose of a given figure.

FIGURES l to 4 are side views of the apparatus chosen for illustration of this invention, shown in four different positions.

FIGURE 5 is a front view of the apparatus approximately in the FIG. 2 position.

FIGURE 6 is a front view of the load carrying assembly, some parts being omitted for clarity.

FIGURE 7 is a vertical sectional view of the load carrying assembly, taken approximately on the line 77 of FIG. 6.

FIGURE 8 is a fragmentary view looking down on the hydraulic means for laterally shifting the carriage.

FIGURE 9 is a view somewhat similar to FIG. 6 but showing the carriage moved to the right and the tilt table tilted to the left, both as viewed.

3,024,933 Patented Mar. 13, 1962 FIGURE 10 is a vertical sectional view through the double swivel reel which pays out one hydraulic hose as the carriage is shifted laterally and takes up the slack in another.

FIGURE 11 is a plan view of the reel structure shown in FIG. 10.

FIGURE 12 is the hydraulic diagram for the apparatus illustrated in earlier figures.

General Description Although the following disclosure offered for public dissemination is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements. The claims at the end hereof are intended as the chief aid toward this purpose, as it is these that meet the requirement of pointing out the parts, improvements, or combinations in which the inventive concepts are found.

The illustrated form of the apparatus includes the chassis 11 carried by wheels 12 preferably all of which are driven and steerable. It performs its work largely by means of boom 13. Boom 13 carries at its end a load engaging assembly 14. The other end of the boom 13 is pivoted to a link structure 16 which is pivoted to the chassis. The boom can be raised and lowered by hydraulic cylinders 17. The link 16 can be pivoted to make the boom reach or retract by hydraulic cylinders 19'.

The load engaging structure 14 includes an A frame 21 pivoted to the boom 13. The A frame 21, through intermediate structure to be described, carries a fork 27.

The A frame 21 may be manipulated by hydraulic cylinders 32 to tip the fork 2'6 forwardly. Thus as seen in FIG. 3 a load may be dumped from the forks by tilting the forks forwardly until the load slides off. Except when it is desired to dump the load, cylinders 32 will normally be retracted to hold the forks 26 horizontal. It is maintained horizontal in spite of the various movements of the boom 13 by a parallelogram type of linkage forming three connected parallelograms. Thus the four corners of the first parallelogram are formed by pivots 31, 33, 36 and 37 (FIG. 2). The link 38 and the portion of the boom 13 are the long sides of the next parallelogram, and the link 16 and the link 35 defines the long sides of the third parallelogram.

Carriage As seen best in FIGURE 7, the A frame 21 carries or includes a frame 41 which as seen best in FIG. 6 is rectangular and of considerable width. FIG. 5 shows that this rectangular portion 41 is substantially the full width of the machine.

As seen best in FIG. 7, this rectangular portion 41 is a track frame. A carriage 42 rides in the track of the frame. Thus the carriage 42 has a downwardly extending flange 43 which rides on rollers 44 along the bottom of the frame 41. As seen best in FIG. 6, the rollers 44 extend the full length of frame 41.

An upper flange 46 of carriage 42 carries a series of rollers 47 which roll along a flange 43 of frame 41.

Rollers similar to the rollers 47 may be carried by the flange 43 of carriage 42 for riding on plate 49 extending the full length of frame 41.

The carriage 42' is shifted laterally by hydraulic power means shown in FIG. 8. A hydraulic cylinder 51 (which is carried by A frame 21 at the position indicated in broken lines in FIG. 7) is provided with a double rod piston. In other words, its piston actuates a rod 52 which extends out from the cylinder 51 at both ends. Each end of rod 52 carries a pulley block 53 comprising. two pulleys. Cooperating with each pulley block 53 is a stationary pulley block 54 carried by the end members of frame 41 (as seen in FIG. 6). Cables 56 are strung around the pulleys, each cable being secured at one end to the end member of frame 41 and at the other end to carriage 42.

From the foregoing it is apparent that when hydraulic fluid is supplied to one end of cylinder 51 it will move the piston toward the other end, and the pulley blocks 53 will be moved in the same direction. One pulley block will draw out cable 56 to pull the carriage 42 in the direction opposite to the movement of piston 52, the other pulley block 53 correspondingly paying out its cable 56.

In this manner, lateral movement of carriage 42 for the full extent of frame 41 is achieved by a simple cylinder and piston actuator.

Tilt Table As seen in FIG. 9, a tilt table 58 can be rocked with respect to carriage 42. The rocking axis is the axis of trunnion 59 seen best in FIG. 7. Trunnion 59 is carried by carriage 42 and has a pivotal bearing engagement with tilt table 58. The upper edge of tilt table 58 is arcuately shaped about the axis of trunnion 59, and it lies behind flange 60, secured to carriage 42. Although anti-friction rollers such as rollers 47 could be provided, it is contemplated that need for this tilting, while extremely heavy loads which would cause excessive friction without the anti-friction rollers, are carried by the forks would be too rare to justify the cost. One chief purpose of the tilting by tilt table 58 is to align the forks 26 with a load to be lifted so that the forks 26 can slip under the load. For example, the load might be horizontally positioned, whereas the ground might be very uneven or slanted, so that the loader as a whole is tipped.

It may be noted at this point that the spacing between the forks 26 may be adjusted manually. Thus, as seen best in FIG. 9, the forks include upright portions 62 having rearward collars 63 sliding on a rod 64 which is carried by tilt table 58. At their lower ends, the uprights 62 may be provided, as seen best in FIG. 7, with rearward lugs 66 interfitting with a flange 67 extending along the bottom of tilt table 58. Bosses 63 may be locked in any position on rod 64, as by set screws 68.

Tilt table 58 may be tilted by a hydraulic cylinder 69 as shown in broken lines in FIG. 6, being located behind tilt table 58. The hydraulic cylinder 69 is pivoted to carriage 42 by which it is carried. The piston rod 71 (FIG. 6) of cylinder 69 is pivoted, as seen in FIG. 7, to a stud 72 extending rearwardly from tilt table 58 through a clear space in carriage 42 which permits movement of stud 72 through the full range of movement corresponding to the full stroke of piston 71. The piston 71 should be in the mid-position of its stroke when the tilt table is positioned to align the forks 26 horizontally with the machine level. Thus tilt table 58 can be tilted equally in either direction from the normal position.

Hydraulic Reel Inasmuch as hydraulic cylinder 69 moves the full distance laterally with the carriage 42, the carrying of hydraulic hoses to it without getting these hydraulic hoses fouled up presents a problem. The problem is solved by the use of a reel 76, the details of which are seen best in FIGS. and 11, and the mounting of which i seen in FIG. 7. As seen in FIG. 7, the reel standard 77 is carried by an angle bar welded to carriage 42.

As seen in FIG. 10, the standard 77 includes two upright portions each of which carries a collar 73 Welded thereto near its top. Through each collar extends a hydraulic fitting 79 which is locked in the collar by a set screw. Each fitting is connected below the collar to a flexible hose 81, these hoses extending (as represented by broken lines in FIG. 7) to the opposite ends of cylinder 69. Each fitting 79 is of L shape, with its horizontal leg comprising a hydraulic swivel 82. From each hydraulic swivel 82 extends a swiveled fitting 33. To'each hydraulic fitting 83 is attached a hose 84. Except for the portions of one or both hoses 84 which are wrapped around shell 86, the hoses extend laterally to the ends of frame 41, where they are connected to other hoses leading to control valves and through them to the source of hydraulic fluid.

The assembly of reel 76 is quite simple. Prior to the insertion of fittings 79 in collars 78, end disk 89 is slipped out of shell 86 with which it fits snugly. Shell 86 is welded to the other end disk 88, so that it remains supported by it. The hoses 84 are now fed through the openings in shell 86 and attached to their respective swivel connections 83. Thereupon the end disk 89 is reapplied to the shell 86, and the fitting 79 are slipped into collars 78.

If the disks 88 and 89 are of two layers, the twolayers are spot welded together to act as one. The inner layer or hub of disk 89 has a press fit in shell 86 or is otherwise made angularly fast with it, so that torque i applied by wound-on portions of hoses 84 through shell 86, and disks 88 and 89 to swivels 83.

When the carriage 42 is in its mid-position, equal amounts of both hoses 84 will be wrapped around the respective ends of shell 86. Of course this amount must be enough to permit the carriage 42 to move all the way to either end of the rectangular frame 41.

Proper winding of the hoses on the reel is ensured by drawing the hoses taut in a condition stretched out in proper alignment with the part of the reel on which each should wind. For this purpose, a coil tension spring 91 (FIG. 6) is secured to a clamp 92 on each hose 84 nearer its outer end than is reached by shell 86, and stretched to a suitable point on the end of rectangular frame 41. The ends of hoses 84 beyond the clamps form loops 93 to permit movement of the clamps 92. Preferably, each hose @4- extends to a fitting which may desirably be in the form of an elbow from which another hose on conduit extends to and along the boom 13, to valves controlled from the drivers seat.

FIGURE 12 shOWs the hydraulic system of the apparatus already described, with the variou cylinder numbered as previously indicated. In addition, steering cylin ders 94 are shown. All of these various cylinders are powered by two twin pumps 96 and 97. These pumps have a common drive so that they will be driven at the same speed, and are matched positive displacement pumps so that they will have equal outputs. Especially, outputs 98 and 99 are equal.

It is important that the two major pump outlets 98 and 99 be connected, each by its own valve 100 or 101, to one end or the other of one of the boom lift cylinders 17. Valves and 108 which are in common housings with valves 100 and 101 may be ignored at this point. At the same time, the boo-m cylinder valves 100 and 101 should be worked simultaneously by a single lever, and hence they have been shown in FIG. 12 as linked together by a link 10 2. If the valves 1% and 101 are fully shifted in the direction for raising the boom, the two pumps 98 and 99 rotating at the same speed will force the same amount of hydraulic fluid into both cylinders 17 and therefore raise the two sides of the boom 13 evenly. Although hydraulic shock absorbers 103 are provided at the connections to the lower ends of cylinders 17, the capacities of these shock absorbers are too small for any expectable inequality of pressure to result in an appreciable inequality of movement of the pistons of cylinders 17.

'Inasmuch as it is extremely unlikely that there will be any need to operate the dumping cylinders 32 while the boom is being raised or lowered, it is practical to use pump outlet '98 for the tilting cylinders also. Accordingly, valve 105, which is paired with valve 100, controls the dumping cylinders 32. By tracing the lines it is seen that outlet 98 is connected to a common inlet for valves 100 and 105, while the common outlet for these valves is connected through return conduit 106 to reservoir 107.

In like manner, outlet 99' may be connected to a common inlet to valves 101 and 108. Valve 108 controls the reaching cylinders 19. This again is practical because it is not essential to operate the reaching cylinders at the same time that the lifting cylinders are being operated. The reaching and dumping cylinders can be operated simultaneously, and this is more likely to be desired. With independent valves and pumps there is no diversion of fluid between reaching and dumping functions, depending on which has the lowest load.

Valves 101 and 108 and valves 100 and 105 are preferably of a type which -by-passes the inflow directly to the outflow or discharge to reservoir, except insofar as this bypass is shut off to direct the flow to a controlled cylinder. Likewise these valves have built in pressure relief characteristics. The relief setting is high, however, so that in normal operation the fluid flow to the cylinders is that determined or metered by the pumps, if the valves are fully thrown. The valves for all of cylinders 17, 19, 32, 51 and 69 have lock positions in which fluid cannot flow to or from either end of the cylinder.

Minor pump outlet 111 is conencted to a pressure relief valve 112 which limits the pressure in the line, and the line extends to a valve 113 called a Universal valve. This valve may be operated to control lateral cylinder 51, connecting the pump outlet 111 to either end and the return to the reservoir to the other end. Another outlet valve 113 makes the fluid pressure from pump outlet 111 available to one steering booster assembly 94 when it is not being utilized for the lateral cylinder 51.

The other minor pump outlet 11 6is similarly connected to valve 117 which can be operated to control tilt table cylinder 69. Alternatively it supplies the other steering booster assembly 94. The steering asesmblies include their own controls, not shown in detail.

Thus it is seen that although only four pump outlets are used for selectively controlling eight cylinder units (treating as one unit each pair of cylinders which is fully connected by one valve), there is never any instance when two of these eight units at different pressures are connected to a single pump outlet so as to cause fluid diversion from a heavy load to a light load. Furthermore, the two lift cylinders, which operate together but may be subjected to very unbalanced loads, are jointly metered to operate alike. The various manipulative movements made practical by this invention can be extremely useful Where the terrain is rough or congested or both. One situation of great utility is in the hold of a ship. For example, this fork lift truck can run beside a bulkhead and still set a load down adjacent to the bulkhead. It is not necessary to back the truck and advance again, if load does not quite jibe with the space for it; the load is merely shifted laterally. A sloping deck usually causes this machine no trouble.

We claim:

1. Loading apparatus including a vehicle having a chassis carried by front and rear wheels, a reaching link pivoted to the chassis and upstanding therefrom, a boom pivoted to the reaching link and extending forwardly therefrom, a frame pivoted to the forward end of the boom, a carriage laterally shiftable on the frame, and a tilt table having a load engaging rack thereon and laterally tiltable on the carriage; said boom including spaced longitudinal members; .a lift cylinder extending between each longitudinal member of the boom and the chassis, a reaching cylinder extending between the reaching link and the chassis, a dumping cylinder extending between the frame and the boom, a lateral shift cylinder controlling movement of the carriage on the frame, a cylinder controlling the tilting of the tilt table, and steering cylinder assemblies separately controlling the steering of the front wheels and rear wheels, a pair of matched positive displacement pumps commonly driven, separate valves linked for common operation but each connected to a separate one of said pumps and to a reservoir for connecting these reversibly to the two ends of one lift cylinder, a valve associated with one of the first named separate valves for connecting the pump and reservoir reversibly to two ends of the dumping cylinder, a valve associated with the second of the first named separate valves for connecting the pump and reservoir reversibly to the two ends of the reaching cylinder, an auxiliary pump, valve means for connecting it and the reservoir reversibly to the opposite ends of the lateral shift cylinder and alternatively connecting this pump to one steering asesmbly, a second auxiliary pump, and valve means for connecting it and a reservoir reversibly to the opposite ends of the tilt cylinder and alternatively connecting this pump to the other steering assembly.

2. Loading apparatus including a vehicle having a chassis carried by front and rear wheels, a reaching link pivoted to the chassis and upstanding therefrom, a boom pivoted to the reaching link and extending forwardly therefrom, a frame pivoted to the forward end of the boom, a carriage laterally shiftable on the frame, and a tilt table having a load engaging rack thereon and laterally tiltable on the carriage; said boom including spaced longitudinal members; a lift cylinder extending between each longitudinal member of the boom and the chassis, a reaching cylinder extending between the reaching link and the chassis, a dumping cylinder extending between the frame and the boom, a lateral shift cylinder controlling movement of the carriage on the frame, a cylinder controlling the tilting of the tilt table, and a pair of matched positive displacement pumps commonly driven, separate valves linked for common operation but each connected to a separate one of said pumps and to a reservoir for connecting these reversibly to the two ends of one lift cylinder, a valve associated with one of the first named separate valves for connecting the pump and reservoir reversibly to two ends of the dumping cylinder, 21 valve associated with the second of the first named separate valves for connecting the pump and reservoir reversibly to the two ends of the reaching cylinder, an auxiliary pump, valve means for connecting it and the reservoir reversibly to the opposite ends of the lateral shift cylinder, a second auxiliary pump, and valve means for connecting it and a reservoir reversibly to the opposite ends of the tilt cylinder.

3. Loading apparatus including a chassis, a boom pivotally carried thereby, a laterally extending track carried at the end of the boom, a carriage moveable laterally along said track, and hydraulic means for controlling the movement of said carriage including a cylinder and piston with its piston rod extending from the cylinder at both ends and block and tackle assemblies, one powered by each of the piston rods for moving the carriage the full extent of the track while the block and. tackle and cylinder and piston structures are con-fined within the lateral extent of the tracks, the block and tackle assemblies each including a span of pulleys, one of the pulleys of each span being disposed close to the end of the track, with a strand of the tackle extending from it to the carriage, the other pulley of each pair being carried by the piston rod.

4. Loading apparatus including a chassis, a boom pivotally carried thereby, a laterally extending track carried at the end of the boom, a carriage moveable laterally along said track, and hydraulic means for controlling the movement of said carriage including a cylinder and piston with a piston rod, and a pair of block and tackle assemblies powered alternately by the cylinder and piston with its two directions of movement for drawing the carriage in either direction the full extent of the track while the block and tackle and cylinder and piston structures are confined within the lateral extent of the tracks, the block and tackle assemblies each including a span of pulleys, one of the pulleys of each span being disposed close to the end of the track, with a strand of the tackle extending from it to the carriage, the other pulley of each pair being carried by the piston rod.

5. Loading apparatus including a chassis, a boom pivotally carried thereby, a laterally extending track carried at the end of the boom, a carriage moveable laterally along said track, and hydraulic means for controlling the movement of said carriage including a cylinder and piston and a pair of block and tackle assemblies powered alternately by the cylinder and piston with its two directions of movement for drawing the carriage in either direction the full extent of the track while the block and tackle and cylinder and piston structures are confined within the lateral extent of the tracks; a tilt table carried by the carriage and to it pivoted for lateral tilting, and a hy draulic motor for controlling the lateral tilting of the tilt table; a pair of conduits connected to said hydraulic motor, a pair of hoses for connection with a hydraulic pump and a reservoir, and swivel drum means for connecting said conduits with said hoses, said swivel drum means being carried by the carriage centrally thereof and having said hoses oppositely wound around the drum and extending from one side thereof in opposite directions so that as the carriage is shifted laterally one hose will be wound up as the other is payed out, each of said hoses being connected to one of said conduits through a hydraulic swivel disposed axially of the drum.

6. Loading apparatus including a power-manipulated track, a carriage moveable laterally along said track, and hydraulic means for controlling the movement of said carriage including a cylinder and piston and a pair of block and tackle assemblies powered alternately by the cylinder and piston with its two directions of movement for drawing the carriage in either direction the full extent of the track while the block and tackle and cylinder and piston structures are confined within the lateral extent of the tracks, a titlt table carried by and pivoted to the carriage for lateral tilting and a hydraulic motor for controlling the lateral tilting of the tilt table; a pair of conduits connected to said hydraulic motor, a pair of hoses for connection with a hydraulic pump and a reservoir, and swivel drum means for connecting said conduits with said hoses, said swivel drum means being carried by the carriage centrally thereof and having said hoses oppositely wound around the drum and extending from one side thereof in opposite directions so that as the carriage is shifted later-ally one hose will be wound up as the other is payed out, each of said hoses being connected to one of said conduits through a hydraulic swivel disposed axially of the drum.

7. Loading apparatus including a power-manipulated track, a carriage moveable laterally along said track, a tilt table carried by and pivoted to the carriage for lateral tilting and a hydraulic motor for controlling the lateral tilting of the tilt table; a pair of conduits connected to said hydraulic motor, a pair of hoses for connection with a hydraulic pump and a reservoir, and swivel drum means for connecting said conduits with said hoses, said swivel drum means being carried by the carriage centrally thereof and having said hoses oppositely wound around the drum and extending from one side thereof in opposite directions so that as the carriage is shifted laterally one hose will be wound up as the other is payed out, each of said hoses being connected to one of said conduits through a hydraulic swivel disposed axially of the drum.

References Cited in the file of this patent UNITED STATES PATENTS 2,348,899 Guignard May 16, 1944 2,457,366 Guerin Dec. 28, 1948 2,522,128 Lehmann Sept. 12, 1950 2,608,315 Turner Aug. 26, 1952 2,621,822 Melin Dec. 16, 1952 2,709,018 Schenkelberger May 24, 1955 2,720,993 Lull Oct. 18, 1955 2,738,087 Arnot Mar. 13, 1956 2,753,060 Lull July 3, 1956 2,782,946 Hough Feb. 26, 1957 2,820,555 Lessmann Jan. 21, 1958 2,820,562 Schenkelberger Jan. 21, 1958 2,887,236 Mindrum May 19, 1959 FOREIGN PATENTS 944,358 Germany June 14, 1956 

